Light is weightless. You can’t touch it or see it. It is energy, not matter. Light is wavy space that travels at an average speed of 186,282 miles in a second. Light vibrates back and forth at different rates, from slow-moving low frequencies to extremely fast, high-energy gamma rays, depending on the source that produces them. The vibrations of light, known as photons, are the result of alternating degrees of resistance and conductivity of space. The range of frequencies that light can produce represents the entire spectrum of electromagnetic energy, including ultraviolet, infrared, x-ray, and the visible light that allows us to see things around us.
A Collection of Writings on Nature, Science, and Art by John Holland